DE-GM 92 01 594 discloses a housing of the kind mentioned in the opening paragraph which is composed of two plastic shells which are provided on the inside with a metal screening. The metal screening may be provided, for example, by vapor deposition or by electroplating.
Owing to more stringent EMI-shielding requirements, metal layers are necessary on the insides of the housings with a thickness of approximately 20 .mu.m to 40 .mu.m. These layer thicknesses can no longer be reliably produced with an equal layer thickness in all locations of the housing by means of vacuum aluminum vapor deposition. Electrochemical layers require an additional surface treatment in order to fulfil the design requirements (paint). Furthermore, the environmental aspects are very critical and recycling is practically impossible.
DE-OS 34 29 353 discloses a plastic framework for appliance housings and components, in particular for mechanical and electromotive appliances, with partial elements made from non-plastic material. In this case, flat or previously shaped plate elements of a component of non-plastic material are laid in position in an injection molding tool and are joined together by means of thermoplastic material in a process which is known per se. In the injection molding tool, the edges of the non-plastic parts are surrounded by the injected thermoplastic material and interconnected thereby. The thermoplastic material grips around the relevant cut edges at one side or at both sides, acting as a claw. Necessary functional elements, for example reinforcement ribs or eyelets for supports and screw connections, may be shaped from thermoplastic material in the same process. The non-plastic inserted flat parts are manufactured in conventional manner as flat stampings or as shaped components such that any necessary holes, recesses, or the like can also be realized.
DE-AS 14 04 394 discloses a method of manufacturing a tub from several layers of synthetic resin. First a comparatively thin plate of thermoplastic material is shaped into a tub as an inner layer of the tub, and subsequently several layers of fiber-reinforced hardenable polymeric resins are provided on the outside of the shaped inner layer, depending on the static requirements, and hardened.
The invention has for its object to improve housings of the kind mentioned in the opening paragraph in view of more stringent requirements for interference protection.